Apparatus for molding tubular concrete bodies



s. LAKE 2,386,961 APPARATUS FOR MOLDING TUBULAR CONCRETE BODIES Oct. 16,1945.

Filed Jan. 26, 1944 2 Sheets-Sheet 1 75 Vacuum- Pressure Oct. 16, 1945.

APPARATUS s. LAKE FOR MOLDING TUBULAR CONCRETE BODIES Filed Jan. 26,.1944 2 Sheets-Sheet 2 on the line 2-2 of Fig. l,

Patented Oct. 16, 1945 UNITED STATES PATENT OFFICE APPARATUS FOR MOLDINGTUBULAR CONCRETE BODIES Simon Lake, Milford, Conn; Thomas A. E. Lakeadministrator of said Simon Lake, deceased Application January 26, 1944,Serial No. 519,804 c 'ZClaims. (.o1.25-30) This invention relates to themolding of con-.

crete, and it has special reference to the moldin of tubular objectssuch as concrete pipes, particularly those which, in service, may besubjected to high internal pressures and to the action of fluids andliquids, such as gases and petroleum products which normally cannot efectively be confined within walls of concrete due to the permeablenature of such walls.

One object of the inventionis to provide for the rapid and uniformmolding of tubular concrete bodies (pipe sections) in such a manner asto subject the concrete mix, during molding, to pressure adequate tothoroughly compact it, at the same time exhausting. from it all air andexcess moisture, thus ensuring a uniform texture free of the blow holesand voids which ordinarily result in the permeability of concrete bodiesmolded in accordance with the usual methods. v

Another objectis to provide for impregnation and/or coating of themolded bodies with-poresealing or other compounds or agents tending toincrease the impermeability of their walls and/or adapting them for usein the handling of substances to which concrete is normally per-.meable, such as corrosive liquids and .gases.

In the accompanying drawings illustrating the invention, in the severalfiguresof which like parts are similarly designated,

flanged casting 6,

Fig. 1 is an axial, sectionalelevation, taken: on the line l-l of Fig.2, showing .one form of apparatus in accordance withthe invention, N

Fig. 2 is a partial sectional elevation taken Fig. 3 is a view similarto Fig. 1, but showing a modified embodiment of apparatus in accordancewith the invention, .and'

Fig. 4 is a partial sectiOnalelevation taken on the line 4-4 of Fig. 3.

As shown in Figs. 1 and 2, preferably made in a vertical flask A, formedin halves and bolted together, with a strip of packing, not shown,between their flanged joints. The flask is bolted to a platen B, setinto a concrete floor slab C, which has a well D, formed below it toreceive the reciprocative hollow core E, which, in operation of theapparatus, forms the inner wall surface of-the pipe. This reciprocatingcore is made of a tube, closed at its lower end as shown at I, and ahydraulic cylinder F is secured at.2 in the. reciprocating core, thiscylinder having a fixedpis ton G shown near the top of the cylinder.- Apiston rod 3' extends from the piston down through a st lf n vb x 4 atthe lower end of the cylinder and out through another stuffing'box 5 atthe lower head I of the reciprocating core, where it is secured in asecured to the floor 1 of the The piston rod 3 is provided with twopassageways. One of these passageways 8 admits toor discharges from thespace 9 above the piston G water or other pressure fluid through pipel0, and the other passageway ll terminates at a port l2 below the pistonandis connected with a pipe [3 which permits water or other pressurefluid to be admitted to or expelled from the space 14 underthe piston.The pipes Ill and I3 are shown as provided with two-way valves l5 andI6, respectively, wherebypressure fluid flow to andfrom the spaces 9 andHi may be controlled.

When fluid-under space. 9 by opening valve 15 on pipe Ill and valve 56is adjusted to permit the fluid of flow out from space l4v underthe'piston, the pressure space 9 will cause thereeiprocating coreE to.

topofcore E and. extension core E is secured to the cone l'l by .aspider. l8 carried by the cone a short distance above the upper end ofcore E, thus leaving an annular space through which concrete may flowfrom the interior of the core extension E into the space between thisextension and the walls of flask A, A heavy piston l9 having a cupleather 20 or. other packing is provided to bear upon a batch ofconcrete mix H dumped into theinterior of the core extension E and forman air tight seal when a vacuum is produced below the cup leather, andthe reciprocating core extension E passes up through a stufling box 2|formedon the bolted cover 22 which closes theupper end of the mold s acebetween the core and the inner walls of the flask A in which space theconcrete forming the pipe is compressed with great force, all as will beexplained later. A pipe 23 leads to a vacuum tank, not shown, and a ringof porous material 214, which is permeable to air and steam but acts asa dam for the concrete, is placed in the top of the mold space.

ressure is. admitted into- Steam may be admitted to the space 25 beit isnecessary to fill all the pores near the inner tween the core E andcylinder F by way of pipe surface of the pipe wall with a sealingcompound, 26 and flexible hose 21, for a purpose hereinafter which maybe composed of any suitable plastic to appearing. suit the specialpurpose for which the pipe is to It is well known that concrete, asusually cast, be used. It has been found that an asphaltum is quiteporous. This porosity may be reduced by compound is very satisfactorywhere the pipe is tamping or by vibration, which causes the air to beused as a water main. In accordance with bubbles liquid, and lightercement particles to the invention this compound may. be. employed riseto ,the top of the mass in the form of in the follow ng mannerzjTheasphaltum is mixed laitance, which should be removed to get a strong,with a small amount of dead oil and a quantity uniform, concreteproduct, i oft powdered pumice or slaked lime, to make a It is also ofimportance in obtaining such a compound which will melt at about 175 F.The product have the casting of the same continuous; ogre E 'E" and theinner surface of the mold A, from start to finish, for, if anystoppageof theare-painted with a layer of this compound which flow ofthe plastic concreteainto the moldoccurs lfi quiqkly hardens into anenamel-like coating and a film of laitance will rise tothe topl ofthe-layer, :hblds litslplace on the core and mold until the thus forminga thin stratum of eak c ncrete pipe is cast. When the core is raised toits top Which might act as a parting place.' position, with the steamturned on, a rapid de- In the production of castings according to thehydration o e o c Occurs. but as long as invention as will now be dscrib d a m h there is some moisture in the concrete mass the sounderairand gas tight pipe can -be manu-- ph t cc'ompound will not melt.However, as factured of concrete than has heretofore been S0011 asrtheConcrete is y, t am w l ap d obtained, and with'or Without metalreinforcing raise theytemperatul'e sufficiently 13118 inthe WanS*theIeOf, a:$ de i d, compound and-it willbe absorbed into the inner {Thevarious parts of the apparatus having been 5 a d u e sur aces cf thecasting and leave anassembled over the well er: pit, as shown, withnular Spaces b e c i and the ,Walls metal reinforcement in place in themold space, the Core E vlizdditional c m ou d if desired a batch H ofproperly mixed concrete, may 110W be forced intdthsespaces at highsufiicient to make the walls tithe ipe, is dumped perature until h a ompetel filled under into the interior of the core extension E and the many P 655111 W h l be dQSPfi he am piston I9 set in place on top-of thebatch. The is now turned o an as $0 sthe o o d valve on pipe 23 isnowopened to the vacuum a q d h y nd heic r s d tank, which drawsa partialvacuum in the space its o m Size} (1116 min th r is hi between-the coreE" and fias k'fA :and throughout r %l" "an enam i u fifl V r fI r h rsis the batch of concrete inthe-core; Atthe same i e iaisa @nquit l'heins o 0f time a pressurefluid,preferably water,.jis admitl Q I P i t iSQ F 'i mS an f t y'fi ted into thespace a and the reciprocatingporeinsulation; ndrita e n el c r s orr s beginsitsjupward travel:Atmospheric pressure, from st met l n er bme t i such due to the" vacuumnow formed beneathpiston |9 is embodied in "the" pipe as castfIf thepipe is to forces the concrete downward, andxthrough the 49 9 used rconveying, gas, Volatileioils, acidu" medium- 0f the'cone H it passesannularly cut-. 1011s qu d ,'d fiercnt kinds of; known tand availwardlyinto the mold space between the core b P t k fi h P013 and Eglll'gandthe Wallsoftheflask A; An'electric ex m j inn n ac h ne-- ovibrator; not" shown; attached to the flask A at T insja paratus i l stt d in. Figs. -3' e fa prepriete point; vibrates the plastic massembodies i eda ted to the inthe'mold'space' and permits anyair bubblesor casting 9 h n ty .of hell and gases that i ht ha b trapped in thebatch spigot'drain pipe,- and also @amodified means for ofconcreteto'rise and beidelivered through pipe molffimpidly forcing the60110119136 into the mold 2 3into'the'vacuumttanlzf 4' space'between thecontinuous core E and flash Therisingspeedofi'the reciprocating core is50 In this m d form the core is-provided' so regulated as to permitthe'iconcreteto flow into with a r t l rfl;carrying a series of theim'qld' paceatany desired rate; and it should involute Shaped b -This b1 eno gh t p t fo a bubbles to tributor is preferably made ofwearresistant be drawn .ofi 'soas to filcrirl a -dense wall. Thischilled Steel or iron as the ,involute shaped den ity Will bestillfurther increased as the lower blades act as cams to pushlthe abrasiveconcrete Dart'E or theeererisee tme to the fact that it. isradiellyrbutwardly u h Openings so formed I slightly lar-eer in diameter[than the extension E circumfiirehtially of P a E21 of the core and actsto compress" the already cast Therqlstnblfltor "1 1S earned by a head Wsection of the pipewall radiallyoutwardly. ls'pmvlded Wlfih ring me 32on the Inner As 'the 'ere startsonf its upward stroke steam O r ced ldepending flange and With-these maybe 'ad itt' 'd'i tg the-space throughcom teeth a pinion 34 meshes, as shown. The pinion,

dfit. Lat/1Tb e-heat 6f the steam transmittd 34 is fixed on one end ofashortshaft 35 having. through'thejwalllof the core E to the concrete in2 1 1 SDacecausesgthe water in the concrete 5 2 -3 5 mi -fi i Weldeg to232 5 3 1??? as itis molded to evaporate and theimoisture thus ng penquare Gr p e is a abearing in'the fixed septum 36, and the othererttttrtairzzetare earths tank wrap-idly asformed' bevel gears 4l. 42.throughthe drive shaft 43,

whfilll h flo fi 93161165 h D bf its gtrrok the whioh may be driven byany appropriate type of heat pf thesteam causes the core E to expand,mitmnsmiss'ion' V 7, Still urther compressing and increasing the -thtth3i revolves freely on a bearin fl n de, lS1,ty-.'0,f the molded,concrete. The steam heathyrdtb'th d fjh hydraulicebylinder F1,

ingshould be continued. riuntil'all' evaporation which reciprocatesuponthe pi st0n ..G., in the ceases; .1 :(To .1 I Ml: same mannerfl'asalreadydescribed in relation to To make an absolutely li'quid and gastight pipe "Fig '1, to ra shn d low t '8 E2;

This modified apparatus is operated as follows: With the core E in itslowered position, as shown, a batch of ready mixed concrete, sumcient inquantity to make the pipe, is dumped into the interior of the core ontop of the distributor 28. The vacuum operated piston is is now set inposition upon the batch and a partial vacuum created through pipe 23within the mold space. This starts a pull on the plastic concrete of thebatch to draw it into the mold space and at the same time starts to pullon the piston I9 to exert pressure on top of the batch of concrete, thusforcing the concrete radially through the series of ports 30. Vibratorsnow being applied to the walls of the flask, the concrete settles in themold space and the core is started to move upward as previouslydescribed in relation to Fig. l. The downward pressure on piston 19combined with the upward movement of the core is sufiicient to fill themold space provided the concrete is fairly wet and free flowing, but ifthe concrete mixture is what is termed a dry mix, with little watercontent, it may require greater power to force the concrete through theports 30 and around the metal reinforcing means, if such are used. Thisis accomplished by rotation of the distributor 28, the involute vanes 29of which will force the concrete through the ports and pack it tightlyin the mold space.

If steam is now admitted through pipe 21 into the steam space 25' in thecore, the moisture in the cast concrete will quickly be evaporated anddrawn off into the vacuum tank, so that, as previously described, aninner lining of a more impervious compound may be forced in tothoroughly fill all pores of the concrete pipe nearest the heated corewalls. This operation is provided for in the modified form of apparatusby means of a pipe M through which grout or other desired compound maybe forced up into the annular perforated pipe 45 and from thereoutwardly through numerous small mating orifices 46 in the core wall.

Various changes and modifications are considered to be within theprinciple of the invention and the scope of the following claims.

What I claim is:

1. Apparatus for molding tubular concrete bodies, including a flask, atubular core of a length substantially twice that of the flask andreciprocative axially of said flask and serving therewith to provide atubular mold space, the interior of substantially one-half the length ofsaid tubular core serving as a receptacle for receiving a batch ofconcrete mix adequate to form the said tubular body, and means forreciprocating said core, said core being provided substantially midwayof its length with means for ejecting the concrete of said batchradially outwardly to fill the mold space progressively from the bottomupwardly as the core moves upon its upward reciprocation, the length ofsaid core providing for its contact with the concrete in the mold spacethroughout the entire molding operation.

2. Apparatus as claimed in claim 1, in which there are provided meansfor subjecting the mold space to suction and means for subjecting saidbatch of concrete mix to atmospheric pressure.

3. Apparatus as claimed in claim 1, in which said core is provided witha piston furnishing a substantially hermetic seal above the batch ofconcrete mix, and the mold space is connected with suction-producingmeans.

4. Apparatus as claimed in claim 1, in which a portion of the core belowsaid radially ejecting means is of greater diameter than the portionabove said means, whereby as the core moves upon its upward moldingreciprocation its portion of greater diameter will radially compress theconcrete progressively deposited in the mold space.

5. Apparatus as claimed in claim 1, in which the portion of the corebelow said radially ejecting means is connected with a source of heatingfluid, whereby, as the mold is progressively filled the concrete thereinmay be dehydrated by the application of heat through said core.

6. Apparatus as claimed in claim 1, in which a rotary distributor havinga plurality of offstanding impeller vanes is provided as a part of saidradially ejecting means.

7. Apparatus for molding tubular concrete bodies, including a flask, anda tubular core of a length substantially twice that of the flask andarranged axially of said flask and serving therewith to provide atubular mold, the interior of said core throughout substantiallyone-half of its length serving as a receptacle for receiving a batch ofconcrete mix adequate to form the said tubular body, and means forcausing relative axial reciprocation between said flask and core, saidcore being provided substantially midway of its length with means thuslocated adjacent to one end of the mold space at one limit of suchreciprocation for ejecting the concrete of said batch radially outwardlyto fill the mold space progressively from said end longitudinally assuch reciprocation progresses.

SIMON LAKE.

